It is known from public prior use that a crane has a jib system, on which an extension and/or an angled arrangement can be provided. EP 1 477 451 A2, DE 36 42 248 A1 and WO 2009/026 870 A1 disclose devices, by means of which an angle position of a jib system can be changed. The drawback is that the angle adjustment of the jib system often needs further aids and/or intermediate steps. A more rapid and easier to handle change of one angle position into another is not possible with the devices mentioned.